1. Field of the Invention
This invention relates to a display device and a structure of backlight module thereof; specifically, the invention relates to a display device that reduces light leakage and a structure of backlight module thereof.
2. Description of the Prior Art
Flat display devices have become the mainstream amongst various types of display devices, wherein home television, monitors for personal computers and laptop computers, and display screens for mobile phone and digital cameras are electronic products that make extensive use of flat display devices. Currently the conventional flat display devices include a backlight module for generating backlight and a display panel that receives backlight and generates images. Furthermore, the backlight module further includes the direct-lit backlight module and the edge-lit backlight module, wherein the direct-lit backlight module is the light source that evenly distributes light amongst the back of the display panel so that the backlight can be evenly transferred to the whole screen. On the other hand, the edge-lit backlight module has its light sources disposed around the display panel. In addition, the edge-lit backlight module transmits the light generated by the light sources at the edges of the display panel to the centre of the display panel via a light guide plate.
FIG. 1A and FIG. 1B are an exploded view and an assembly view of a conventional edge-lit backlight module 10. As FIG. 1A shows, the conventional edge-lit backlight module 10 includes a light source module 11, a backplate 20, a frame body 30, an optical film 40, and a light guide plate 50. The frame body 30 is disposed in an accommodation space 22 enclosed by the sidewall 21 of the backplate 20 and is used to accommodate the light source module 11, the optical film 40, and the light guide plate 50. When the backlight module 10 is assembled, the light sources 12 of the light source module 11 will generate light which pass through the light guide plate 50 and the optical film 40 to reach the display panel (not illustrated).
Furthermore, in order to fix the position of the optical film 40, the frame body 30 and the optical film 40 illustrated in FIG. 1A and FIG. 1B have a concave portion 31 and a protrusion portion 41 respectively, wherein the protrusion portion 41 extends from the edge of the optical film 40 and enters the concave portion 31 formed at the edge of the frame body 30. In this way, the protrusion portion 41 can be positioned at the concave portion 31 of the frame body 30 in order to fix the relative position between the optical film 40 and other elements.
However, as FIG. 1B shows, the concave portion 31 corresponding to the protrusion portion 41 forms a gap at the side wall of the frame body 30 and the gap will expose at least a portion of the inner surface of the sidewall 21 of the backplate 20. FIG. 1C is cross-sectional view along the line AA′ on the conventional backlight module 10 illustrated in FIG. 1B, wherein a display panel 60 is disposed on the conventional backlight module 10. The backplate 20 of the conventional edge-lit backlight module 10 is normally made of light-reflective metal. Therefore, light generated by the light source module 11 will pass through the optical film 40 and contact the sidewall 21 of the backplate 20, where the light is then reflected to the top of the edge of the optical film 40. The above-mentioned light will pass through the display panel 60 above the backlight module 10 and forms light leakages at the edge of the display panel 60.